U.S. patent application number 14/246379 was filed with the patent office on 2015-01-22 for direct-current uninterruptible power supply system and device.
This patent application is currently assigned to LITE-ON TECHNOLOGY CORP.. The applicant listed for this patent is LITE-ON ELECTRONICS (GUANGZHOU) LIMITED, LITE-ON TECHNOLOGY CORP.. Invention is credited to MING-WANG CHENG, WEI-LIEH LAI, YI-NAN LAI, LIANG-CHUN LIN.
Application Number | 20150021989 14/246379 |
Document ID | / |
Family ID | 52343016 |
Filed Date | 2015-01-22 |
United States Patent
Application |
20150021989 |
Kind Code |
A1 |
LIN; LIANG-CHUN ; et
al. |
January 22, 2015 |
DIRECT-CURRENT UNINTERRUPTIBLE POWER SUPPLY SYSTEM AND DEVICE
Abstract
A DC uninterruptible power supply system includes plural
uninterruptible power supply devices, each of which includes a
power cord, a battery module, a voltage detecting circuit, a
current detecting circuit, and a control unit. When the voltage
detecting circuit detects that a voltage at the power cord is lower
than a first preset value, the control unit controls the battery
module to output electrical power to the power cord. When the
current detecting circuit detects that current of another
uninterruptible power supply device is smaller than a second preset
value, the control unit controls a switch to permit current flow to
the another uninterruptible power supply device.
Inventors: |
LIN; LIANG-CHUN; (TAIPEI,
TW) ; LAI; YI-NAN; (TAIPEI, TW) ; LAI;
WEI-LIEH; (TAIPEI, TW) ; CHENG; MING-WANG;
(TAIPEI, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LITE-ON TECHNOLOGY CORP.
LITE-ON ELECTRONICS (GUANGZHOU) LIMITED |
Taipei
Guangzhou |
|
TW
CN |
|
|
Assignee: |
LITE-ON TECHNOLOGY CORP.
Taipei
TW
LITE-ON ELECTRONICS (GUANGZHOU) LIMITED
Guangzhou
CN
|
Family ID: |
52343016 |
Appl. No.: |
14/246379 |
Filed: |
April 7, 2014 |
Current U.S.
Class: |
307/23 ;
307/66 |
Current CPC
Class: |
H02J 9/061 20130101;
Y04S 20/20 20130101; Y02B 70/30 20130101; H02J 9/068 20200101; H02J
9/06 20130101 |
Class at
Publication: |
307/23 ;
307/66 |
International
Class: |
H02J 9/06 20060101
H02J009/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 22, 2013 |
CN |
201310309809.8 |
Claims
1. A direct-current (DC) uninterruptible power supply system,
comprising a plurality of uninterruptible power supply devices,
each of which is disposed to receive input from a DC power source
for supply of electrical power to a load, and includes: a power
cord to be coupled between the load and the DC power source for
transmitting a first current from the DC power source to the load;
a battery module coupled to said power cord for receiving and
storing electrical power from the DC power source; a voltage
detecting circuit coupled to said power cord and configured to
generate a first trigger signal upon detecting that a voltage of
the DC power source is lower than a first preset value; a current
detecting circuit coupled to said power cord of another one of said
uninterruptible power supply devices, and configured to generate a
second trigger signal upon detecting that the first current flowing
in said power cord of said another one of said uninterruptible
power supply devices is smaller than a second preset value; a
switch coupled between said power cord and said current detecting
circuit, and configured to make or break electrical connection
between said power cord and said current detecting circuit; and a
control unit coupled to said battery module, said voltage detecting
circuit, said current detecting circuit and said switch, and
configured to control said battery module to output electrical
power to said power cord according to the first trigger signal, and
to control said switch to make electrical connection between said
power cord and said current detecting circuit according to the
second trigger signal.
2. The DC uninterruptible power supply system as claimed in claim
1, wherein, for each of said uninterruptible power supply devices,
said current detecting circuit is further configured to generate a
third trigger signal upon detecting that a second current flowing
through said switch is greater than a third preset value, said
control unit being further configured to control said switch to
break electrical connection between said power cord and said
current detecting circuit according to the third trigger
signal.
3. The DC uninterruptible power supply system as claimed in claim
2, wherein said current detecting circuit is further configured to,
when said switch makes electrical connection between said power
cord and said current detecting circuit, generate a fourth trigger
signal upon detecting that the first current flowing in said power
cord of said another one of said uninterruptible power supply
devices reaches a fourth preset value, said control unit being
further configured to control said switch to break electrical
connection between said power cord and said current detecting
circuit according to the fourth trigger signal.
4. The DC uninterruptible power supply system as claimed in claim
1, wherein said current detecting circuit is further configured to,
when said switch makes electrical connection between said power
cord and said current detecting circuit, generate a third trigger
signal upon detecting that the first current flowing in said power
cord of said another one of said uninterruptible power supply
devices reaches a third preset value, said control unit being
further configured to control said switch to break electrical
connection between said power cord and said current detecting
circuit according to the third trigger signal.
5. A direct-current (DC) uninterruptible power supply device
disposed to receive input from a DC power source for supply of
electrical power to a load, comprising: a power cord to be coupled
between the load and the DC power source for transmitting a first
current from the DC power source to the load; a battery module
coupled to said power cord for receiving and storing electrical
power from the DC power source; a voltage detecting circuit coupled
to said power cord and configured to generate a first trigger
signal upon detecting that a voltage of the DC power source is
lower than a first preset value; a current detecting circuit to be
coupled to an external power cord and configured to generate a
second trigger signal upon detecting that a current flowing in the
external power cord is smaller than a second preset value; a
power-cord switch coupled between said power cord and said current
detecting circuit, and configured to make or break electrical
connection between said power cord and said current detecting
circuit; and a control unit coupled to said battery module, said
voltage detecting circuit, said current detecting circuit and said
power-cord switch, and configured to control said battery module to
output electrical power to said power cord according to the first
trigger signal, and to control said power-cord switch to make
electrical connection between said power cord and said current
detecting circuit according to the second trigger signal.
6. The DC uninterruptible power supply device as claimed in claim
5, wherein said battery module includes: a battery unit; a charging
circuit coupled between said power cord and said battery unit for
receiving electrical power from the DC power source and charging
said battery unit; and a discharging circuit coupled between said
power cord and said battery unit for outputting electrical power
from said battery unit to said power cord; wherein said control
unit controls said battery unit to output electrical power to said
discharging circuit according to the first trigger signal.
7. The DC uninterruptible power supply device as claimed on claim
6, wherein said charging circuit includes a DC-DC converter coupled
to said power cord, and a charge switch configured to make or break
electrical connection between said DC-DC converter and said battery
unit, said DC-DC converter being configured to convert the voltage
from the DC voltage source into a rating voltage of said battery
unit, and to charge said battery unit via said charge switch.
8. The DC uninterruptible power supply device as claimed in claim
6, wherein said discharging circuit includes a linear regulator
coupled to said battery unit, and a discharge switch configured to
make or break electrical connection between said linear regulator
and said power cord, said linear regulator being configured to
adjust a voltage outputted by said battery unit to have a magnitude
substantially the same as that of the voltage from the DC power
source, and to output the voltage adjusted thereby to said power
cord via said discharge switch.
9. The DC uninterruptible power supply device as claimed in claim
6, wherein said control unit includes a battery management module
coupled to said battery unit, and a controller coupled to said
battery management module, said voltage detecting circuit, said
current detecting circuit, and said power-cord switch, said
controller being configured to control output of electrical power
by said battery unit via said battery management module according
to the first trigger signal, and to control said power-cord switch
to make electrical connection between said power cord and said
current detecting circuit according to the second trigger
signal.
10. The DC uninterruptible power supply device as claimed in claim
5, wherein said current detecting circuit is further configured to
detect a second current flowing to the external power cord via said
power cord, and to generate a third trigger signal upon detecting
that the second current is greater than a third preset value, said
control unit being further configured to control said power-cord
switch to break electrical connection between said power cord and
said current detecting circuit according to the third trigger
signal.
11. The DC uninterruptible power supply device as claimed in claim
10, wherein said current detecting circuit is further configured
to, when said power-cord switch makes electrical connection between
said power cord and said current detecting circuit, generate a
fourth trigger signal upon detecting that the current flowing in
the external power cord reaches a fourth preset value, said control
unit being further configured to control said power-cord switch to
break electrical connection between said power cord and said
current detecting circuit according to the fourth trigger
signal.
12. The DC uninterruptible power supply device as claimed in claim
5, wherein said current detecting circuit is further configured to,
when said power-cord switch makes electrical connection between
said power cord and said current detecting circuit, generate a
third trigger signal upon detecting that the current flowing in the
external power cord reaches a third preset value, said control unit
being further configured to control said power-cord switch to break
electrical connection between said power cord and said current
detecting circuit according to the third trigger signal.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to Chinese Application No.
201310309809.8, filed on Jul. 22, 2013.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to an uninterruptible power supply
system and device, and more particularly to a direct-current
uninterruptible power supply system and device of a direct-current
power source.
[0004] 2. Description of the Related Art
[0005] Referring to FIG. 1, a conventional uninterruptible power
supply device 1 includes a voltage distribution unit 11 that
converts electrical power from a three-phase alternating-current
(AC) power source 300 to single-phase electrical power, and a power
supply unit 13 that converts the single-phase electrical power
provided by the voltage distribution unit 11 to direct-current (DC)
electrical power. The DC electrical power outputted by the power
supply unit 13 is provided to a server 200, and also to a charging
circuit 31 that converts the DC electrical power to a rating
voltage of a battery 33 for charging the battery 33. The battery 33
is coupled to a transformer module 35. A switch 37 is coupled
between the transformer module 35 and the server 200 and is
controlled by the power supply unit 13. When the AC power source
300 stops output of electrical power, the power supply unit 13
controls the switch 37 to make electrical connection between the
transformer module 35 and the server 200, so that the battery 33
outputs electrical power that is subsequently converted by the
transformer module 35 to DC electrical power required by the server
200. The converted DC electrical power is then provided to the
server 200 through the switch 37, thus achieving uninterrupted
power supply.
[0006] However, the conventional uninterruptible power supply
device 1 is only suitable for a single load, and cannot be
connected to another uninterruptible power supply device, so that
the load of the another uninterruptible power supply device cannot
obtain additional electrical power when required. Furthermore, the
transformer module 35 of the conventional uninterruptible power
supply device 1 is usually implemented using a switching DC-DC
converter, which is relatively complicated and has a relatively
large size, making it difficult to reduce the size of the
uninterruptible power supply device 1, and thus disfavoring
application to electronic products that tend to have a light weight
and a small size.
SUMMARY OF THE INVENTION
[0007] Therefore, an object of the present invention is to provide
a DC uninterruptible power supply system that includes a plurality
of DC uninterruptible power supply devices which may serve as
backup power sources for each other, so that each of the DC
uninterruptible power supply devices may promptly provide
electrical power to another DC uninterruptible power supply device
coupled thereto when required.
[0008] According to one aspect of the present invention, a
direct-current (DC) uninterruptible power supply system comprises a
plurality of uninterruptible power supply devices, each of which is
disposed to receive input from a DC power source for supply of
electrical power to a load, and includes:
[0009] a power cord to be coupled between the load and the DC power
source for transmitting a first current from the DC power source to
the load;
[0010] a battery module coupled to the power cord for receiving and
storing electrical power from the DC power source;
[0011] a voltage detecting circuit coupled to the power cord and
configured to generate a first trigger signal upon detecting that a
voltage of the DC power source is lower than a first preset
value;
[0012] a current detecting circuit coupled to the power cord of
another one of the uninterruptible power supply devices, and
configured to generate a second trigger signal upon detecting that
the first current flowing in the power cord of the another one of
the uninterruptible power supply devices is smaller than a second
preset value;
[0013] a switch coupled between the power cord and the current
detecting circuit, and configured to make or break electrical
connection between the power cord and the current detecting
circuit; and
[0014] a control unit coupled to the battery module, the voltage
detecting circuit, the current detecting circuit and the switch,
and configured to control the battery module to output electrical
power to the power cord according to the first trigger signal, and
to control the switch to make electrical connection between the
power cord and the current detecting circuit according to the
second trigger signal.
[0015] Another object of the present invention is to provide a DC
uninterruptible power supply device that may have a relatively
small size and a relatively quick response.
[0016] According to another aspect of the present invention, a
direct-current (DC) uninterruptible power supply device is disposed
to receive input from a DC power source for supply of electrical
power to a load, and comprises:
[0017] a power cord to be coupled between the load and the DC power
source for transmitting a first current from the DC power source to
the load;
[0018] a battery module coupled to the power cord for receiving and
storing electrical power from the DC power source;
[0019] a voltage detecting circuit coupled to the power cord and
configured to generate a first trigger signal upon detecting that a
voltage of the DC power source is lower than a first preset
value;
[0020] a current detecting circuit to be coupled to an external
power cord and configured to generate a second trigger signal upon
detecting that a current flowing in the external power cord is
smaller than a second preset value;
[0021] a power-cord switch coupled between the power cord and the
current detecting circuit, and configured to make or break
electrical connection between the power cord and the current
detecting circuit; and
[0022] a control unit coupled to the battery module, the voltage
detecting circuit, the current detecting circuit and the power-cord
switch, and configured to control the battery module to output
electrical power to the power cord according to the first trigger
signal, and to control the power-cord switch to make electrical
connection between the power cord and the current detecting circuit
according to the second trigger signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Other features and advantages of the present invention will
become apparent in the following detailed description of the
preferred embodiment with reference to the accompanying drawings,
of which:
[0024] FIG. 1 is a circuit block diagram illustrating a
conventional uninterruptible power supply device;
[0025] FIG. 2 is a circuit block diagram illustrating a preferred
embodiment of a direct-current (DC) uninterruptible power supply
device according to the present invention;
[0026] FIG. 3 is a schematic circuit diagram illustrating a DC
uninterruptible power supply system that includes a plurality of
the preferred embodiment of the DC uninterruptible power supply
devices coupled together, which may mutually support each other
when providing electrical power; and
[0027] FIG. 4 is a circuit block diagram illustrating circuit
blocks of the preferred embodiment of the DC uninterruptible power
supply device in greater detail and linking relationships among the
blocks.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0028] Referring to FIG. 2, the preferred embodiment of the
direct-current (DC) uninterruptible power supply device 2 according
to this invention is shown to receive input from a DC power source
3 for supply of electrical power to a load 4, and is adapted to be
coupled to another DC uninterruptible power supply device 5. The DC
uninterruptible power supply device 2 includes a power cord 21, a
battery module 22, a voltage detecting circuit 23, a power-cord
switch 24, a current detecting circuit 25 and a control unit 26.
The power cord 21 is coupled between the load 4 and the DC power
source 3 for supply of electrical power from the DC power source 3
to the load 4. In this embodiment, the load 4 may be any kind of
electronic device or electronic equipment that uses DC electrical
power, such as a notebook computer, a server, etc. In the
implementation shown in FIG. 2, the DC uninterruptible power supply
device 5 and the DC uninterruptible power supply device 2 of the
preferred embodiment have an identical circuit configuration, and
the current detecting circuit 25 is designed to be coupled between
the power cord 21 and a power cord 51 of the DC uninterruptible
power supply device 5 through the power-cord switch 24. The
power-cord switch 24 is coupled between the power cord 21 and the
current detecting circuit 25, and is controlled by the control unit
26 to make or break electrical connection between the current
detecting circuit 25 and the power cord 21.
[0029] The battery module 22 is coupled to the power cord 21 for
receiving and storing electrical power from the DC power source 3,
and includes a charging circuit 221, a battery unit 222 and a
discharging circuit 223. The charging circuit 221 is coupled
between the power cord 21 and the battery unit 222 for receiving
electrical power from the DC power source 3 and charging the
battery unit 222. The battery unit 222 may be implemented using
conventional rechargeable batteries coupled in series, in parallel,
or in series-parallel, where the conventional rechargeable
batteries may be Li-ion batteries, NiMH batteries, NiCd batteries,
lead-acid batteries, etc. The discharging circuit 223 is used for
adjusting a voltage outputted by the battery unit 222 to have a
magnitude substantially the same as that of a voltage Vdc from the
DC power source 3 (i.e., a voltage required by the load 4).
[0030] The voltage detecting circuit 23 is coupled to the power
cord 21 for detecting the voltage Vdc of the DC power source 3, and
generates a first trigger signal upon detecting that the voltage
Vdc of the DC power source 3 is lower than a first preset value.
The current detecting circuit 25, which is coupled between the
power-cord switch 24 and the power cord 51 of the DC
uninterruptible power supply device 5, detects a first current
I.sub.1 flowing in the power cord 51 of the DC uninterruptible
power supply device 5, and generates a second trigger signal upon
detecting that the first current I.sub.1 is smaller than a second
preset value. The control unit 26 is coupled to the battery module
22, the voltage detecting circuit 23, the current detecting circuit
25 and the power-cord switch 24, and controls the battery module 22
to output electrical power to the power cord 21 according to the
first trigger signal, and controls the power-cord switch 24 to make
electrical connection between the power cord 21 and the current
detecting circuit 25 according to the second trigger signal.
[0031] Therefore, when the control unit 26 receives the first
trigger signal from the voltage detecting circuit 23, which
represents abnormal supply of electrical power by the DC power
source 3 (e.g., cease of power supply or unstable power supply),
the control unit 26 controls the battery module 22 to output
electrical power to the power cord 21 for the load 4, thereby
achieving uninterrupted power supply to the load 4.
[0032] When supply of electrical power by the DC power source 3 is
normal and the control unit 26 receives the second trigger signal
from the current detecting circuit 25, which represents that the DC
uninterruptible power supply device 5 is unable to supply power
normally, the control unit 26 immediately controls the power-cord
switch 24 to make electrical connection between the power cord 21
and the current detecting circuit 25, so that the DC power source 3
may promptly supply electrical power to the load 6 that is coupled
to the power cord 51 of the DC uninterruptible power supply device
5 via the power cord 21, the power-cord switch 24 and the current
detecting circuit 25, thereby achieving uninterrupted power supply
to the load 6 that is coupled to the DC uninterruptible power
supply device 5. Even if electrical power is supplied by the
battery module 22 due to abnormal power supply by the DC power
source 3, the electrical power may also be provided to the load 6
that is coupled to the DC uninterruptible power supply device 5
through the power cord 21, the power-cord switch 24, and the
current detecting circuit 25.
[0033] Furthermore, when the power-cord switch 24 makes electrical
connection between the power cord 21 and the current detecting
circuit 25, the current detecting circuit 25 generates a third
trigger signal that is provided to the control unit 26 upon
detecting a second current I.sub.2 that flows in the power cord 21
from the DC uninterruptible power supply device 2 to the DC
uninterruptible power supply device 5 (i.e., that flows through the
power-cord switch 24) is greater than a third preset value (i.e.,
overcurrent), for example, when a short circuit occurs in the DC
uninterruptible power supply device 5. The control unit 26 controls
the power-cord switch 24 to break electrical connection between the
power cord 21 and the current detecting circuit 25 according to the
third trigger signal so as to prevent possible damage to circuits
of the DC uninterruptible power supply device 2 from the
overcurrent.
[0034] In addition, when the DC uninterruptible power supply device
5 is restored to normal supply of electrical power, and the current
detecting circuit 25 detects that the first current I.sub.1 flowing
in the power cord 51 of the DC uninterruptible power supply device
5 reaches a fourth preset value, the control unit 26 controls the
power-cord switch 24 to break electrical connection between the
power cord 21 and the current detecting circuit 25 according to the
fourth trigger signal so as to stop supply of electrical power to
the DC uninterruptible power supply device 5.
[0035] FIG. 3 shows a DC uninterruptible power supply system 400
that includes a plurality of the DC uninterruptible power supply
devices U1.about.Un according to the preferred embodiment coupled
in series through the power-cord switches S1.about.Sn thereof. When
one of the DC uninterruptible power supply devices U1.about.Un, for
example, the DC uninterruptible power supply device U3, is unable
to normally provide electrical power to its load L3, the DC
uninterruptible power supply device U2 may immediately detect such
a condition, and control the power-cord switch 52 to make
electrical connection between the power cords of the DC
uninterruptible power supply devices U2 and U3, so as to supply
electrical power promptly to the load L3 that is coupled to the DC
uninterruptible power supply device U3. Similarly, when the DC
uninterruptible power supply device U2 is unable to normally
provide electrical power, the DC uninterruptible power supply
device U1 may supply electrical power promptly to the DC
uninterruptible power supply device U2, thereby achieving mutual
support when providing electrical power.
[0036] FIG. 4 shows a detailed block diagram for the battery module
22 and the control unit 26 of the DC uninterruptible power supply
device 2 of the preferred embodiment. The charging circuit 221 of
the battery module 22 includes a DC-DC converter 224 coupled to the
power cord 21 and a charge switch 225. The discharging circuit 227
includes a linear regulator 226 coupled to the battery unit 222,
and a discharge switch 227 coupled between the linear regulator 226
and the power cord 21. The control unit 26 includes a battery
management module 261 coupled to the battery unit 222, and a
controller 262.
[0037] The DC-DC converter 224 is configured to convert the voltage
Vdc from the DC voltage source 3 into a rating voltage of the
battery unit 222, and to charge the battery unit 222 via the charge
switch 225. The DC-DC convertor 224 and the charge switch 225 are
respectively controlled using a first control signal CS1 and a
second control signal CS2 outputted by the controller 262 of the
control unit 26. For example, before receipt of the first trigger
signal, the controller 262 controls the charging circuit 221 to
charge the battery unit 222 until reaching full charge. After
receipt of the first trigger signal, the controller 262 controls
output of electrical power by the battery unit 222 via the battery
management module 261 according to the first trigger signal. Since
the DC power source 3 is unable to normally supply electrical power
at this time, the controller 262 controls the charging circuit 221
to temporarily stop charging the battery unit 222 until the DC
power source 3 is restored to normal supply of electrical
power.
[0038] In addition, the controller 262 further outputs a third
control signal DS1 and a fourth control signal DS2 to respectively
control operations of the linear regulator 226 and the discharge
switch 227, such that the linear regulator 226 applies a voltage
drop to a voltage outputted by the battery unit 222 for outputting
a voltage that has a magnitude suitable for the load 4 (i.e.,
substantially the same as that of the voltage Vdc from the DC power
source 3), and outputs the voltage adjusted thereby to the power
cord 21 via the discharge switch 227. For example, after receipt of
the first trigger signal, the controller 262 controls the
discharging circuit 223 to operate, so as to output a voltage
having a magnitude that is the same as that of the DC power source
3 to the power cord 21 for the load 4 until the DC power source 3
is restored to normal supply of electrical power.
[0039] It should be noted that the linear regulator 226 of the
discharging circuit 223 used in this embodiment is a low dropout
(LDO) regulator, which has advantages such as a relatively quick
response, low power consumption, a small size, low cost, etc., so
as to reduce the size, power consumption, and cost of the DC
uninterruptible power supply device 2, and to promote response
speed of the discharging circuit 223 and the DC uninterruptible
power supply device 2.
[0040] To sum up, by virtue of the power-cord switch 24 and the
current detecting circuit 25 that are coupled between the power
cord 21 and another DC uninterruptible power supply device 5 in
this embodiment, the second trigger signal is generated when the
current detecting circuit 25 detects abnormal power supply by the
DC uninterruptible power supply device 5, so as to enable control
of the power-cord switch 24 to make electrical connection between
the power cord 21 and the current detecting circuit 25, thereby
promptly supplying electrical power to the load 6 of the DC
uninterruptible power supply device 5 via the power cord 21, and
achieving mutual support when providing electrical power. Moreover,
using the linear regulator 226 as a voltage drop converting circuit
in the discharging circuit 223 may reduce an overall size, power
consumption and cost of the DC uninterruptible power supply device
2, and may enhance response time performance of the discharging
circuit 223 and the DC uninterruptible power supply device 2.
[0041] While the present invention has been described in connection
with what is considered the most practical and preferred
embodiment, it is understood that this invention is not limited to
the disclosed embodiment but is intended to cover various
arrangements included within the spirit and scope of the broadest
interpretation so as to encompass all such modifications and
equivalent arrangements.
* * * * *